The present invention refers to an automatic compressed air or gas distributor located or not at the end of a jack piston and which, after having been activated, works automatically owing to the pressure and depression of the air into the jack.
The present invention also relates to a realization in the form of a kit, or integrated into any mobile assembly actuated by compressed air or pneumatic pressure (possibly a gas under pressure other than air).
Several types of compressed air distributors are already known, but all of them are actuated by mechanical, electromechanical or electronic means, without offering a possibility of automatic closing and admission of the compressed air according to an air pressure/depression, as well as the automatic release of the air at the time the jack piston returns back.
Weapons and more especially compressed air guns are the favorite technical field for such devices. Generally speaking, the air compressed by a mechanical mean, actuated by the operator at the time of loading (hand pump) or a compressed gas such as carbon dioxide contained in a cartridge, is released from a stocking chamber to the weapon barrel. This release is made by means of a valve actuated by pressure on the trigger.
For example, the U.S. Pat. No. 5,400,536 describes a double action pistol with a rotary cylinder, showing a jack in line with the barrel to fire projectiles. At the time of firing, a rod solid with the jack piston, is hit by the hammer with the effect to open the valve and to release a gas under pressure into the barrel.
The U.S. Pat. No. 5,613,483 discloses a piston and cylinder assembly for a gas weapon. The piston can move from backward to forward position between a loading position and a firing position. The piston moves through two chambers appearing in the cylinder. When the piston is in loading position, the cylinder communicates, via the first chamber, with a device supplying gas under pressure. This position of the piston prevents any communication between the two chambers.
On the other hand, in firing position, there is no longer communication between the first chamber and the gas supply, but there is a communication between the two chambers which allows the gas to pass from the first to the second chamber. To achieve that goal, the piston rod has a longitudinally located pass section at the connection with the cylinder.
Finally, U.S. Pat. No. 5,363,834 describes a weapon with a first operating mode for the launching of a projectile by means of compressed gas contained in a cartridge and a second operating mode for the launching by means of compressed air produced by a hand operated pump mechanism. The objective is to possibly remedy a failure in the device supplying compressed gas (carbon dioxide). A manual switch operated by the shooter allows to select one mode or the other, by connecting one stocking chamber with the compressed air or with the compressed air produced by pumping. When firing, the hammer hits a component of jack piston which releases the air or the gas under pressure towards the gun barrel.
None of the compressed air distributors described here above offers an automatic functioning mode. Furthermore, these very complicated devices are not compatible with the design of a distributor introduced in kit form. Then, in the armament field, for example, it is more and more desirable to proceed with functional simulations, that is to say, without launching a projectile, but by reproducing accurately all the normal functions of the weapon such as the displacement of the mobile parts together with the resulting recoil, the trigger pull weight etc. Such simulations call for example for the sending of a laser beam to the target. The laser beam can be triggered by an electric switch hit by a valve piston.
There is then a potential interest to develop an automatic jack system.
The present invention aims to provide a jack and its compressed gas distributor, preferably in line, offering a fully automatic functioning after activation by an initial impulse.
The invention has the additional aim to possibly supply, for some applications, such a jack together with its distributor, as a kit which can be easily adapted to existing equipment.
The invention also aims to supply such a distributor compact enough, that is to say, causing a very light increase of the jack length by integrating the distributor, simple and easy to produce.
Finally, the invention aims to propose an automatic pneumatic distributor to be used in many technical applications and not limited to the specific armament technical field.
The present invention relates to an automatic functioning device for distributing compressed gas, for example compressed air or compressed carbon dioxide, comprising a jack made of a cylinder in which can slide a piston having a piston head, a distributor with an intake of compressed gas fitting said cylinder at one front end to be sealed, called distributor support and a chamber, capable to contain said compressed gas under pressure and being dynamically located between the end of the cylinder to be sealed and the piston head.
The device of the invention additionally includes means for successively and automatically carrying out the following operations, after the piston has been initially struck on a rear end by a hammer:
forward piston displacement, compressed gas intake into the chamber and pressurization of the latter;
rearward recoil of the piston, release of the compressed gas contained in the chamber and depressurization of the latter;
return of the piston to the front, closing of the compressed gas intake, release to the front of the remaining gas contained within the chamber and return of the device to its initial position.
According to one preferred embodiment of the invention, the device includes a valve capable of opening and closing along the cylinder axis and a double sealing ring allowing the opening and closing of the compressed gas intake, said valve being fitted with a first return spring such as, in its balanced position, it is disengaged from the double ring at its rear side, the double ring being fitted with a second return spring such as, in its balanced position, it seals the compressed gas intake.
Advantageously, the piston head can come in contact at the front of the cylinder with the valve which causes the joint recoil of said valve and the double ring fully against the distributor support which in turn causes compressed gas intake into the chamber.
Preferably, the piston is fitted with a return spring which tends to bring it back to its balanced position at the front of the cylinder.
According to the invention, at the time when the depressurization of the chamber occurs owing to the piston return to the rear, the gas under pressure escapes by the coming out of the piston out of the cylinder.
In an alternative preferred embodiment, at the time when the depressurization of the chamber occurs owing to the piston return to the rear, the gas under pressure escapes through an aperture located in the cylinder, the piston remaining in this case inside the cylinder.
Still according to the invention, the chamber being at most lightly pressurized and the piston being not in contact with the valve, said valve and said double ring are in their balanced position owing to the effect of their respective return springs and the valve is disengaged from the double ring which allows an escape of the gas contained in the chamber through an aperture located in the wall of the distributor support, said double ring being in a closing position of the pressurized gas intake.
According to a first embodiment, a distributor control is effected by contact between the piston and the valve by means of a striker capable of sliding freely inside the piston, after the rear side of the striker has been initially hit by the hammer.
According to a second embodiment, a distributor control is effected by a pulling device located in front of the assembly composed of the distributor and its jack.
The fact to offer a very compact assembly allows to considerably reduce losses of compressed air due to an otherwise great distance between the distributor and the jack.
Another advantage lies in the capability to re-cock very easily the distributor activation device by the piston recoil.
The device jack/distributor of the present invention is advantageously usable with pistol-type weapons (i.e. equipped with a slide) or with rifles (i.e. equipped with a breech block).